Risk Analysis Commons^™

Wind-Wave Misalignment Effects On Multiline Anchor Systems For Floating Offshore Wind Turbines, Doron T. Rose

Masters Theses

Multiline anchors are a novel way to reduce the cost of arrays of floating offshore wind turbines (FOWTs), but their behavior is not yet fully understood. Through metocean characterization and dynamic simulations, this thesis investigates the effects of wind-wave misalignment on multiline anchor systems. Four coastal U.S. sites are characterized in order to develop IEC design load cases (DLCs) and analyze real-world misaligned conditions. Stonewall Bank, Oregon showed the highest 500-year extreme wave height, at 16.6 m, while Virginia Beach, Virginia showed the highest 500-year wind speed, at 56.8 m/s. Misalignment probability distributions, at all sites, are found to converge …

Load Modeling And Evaluation Of Leds For Hardware Test Bed Application, Jillian M. Ruff

Masters Theses

The lighting industry was revolutionized with the emergence of LED lighting. Over the last 15 years, LED lighting device sales and utilization have grown immensely. The growth and popularity of LEDs is due to improved operation of the device when compared to previous lighting technologies. Efficient performance of the device is critical due to the growth of global energy consumption.

As nonrenewable generation fuel is finite, utilities have begun the transition to renewable energy generation. Generation and distribution systems become inherently complex to comprehend and maintain with incorporation of emerging supply and load technologies. With the unprecedented growth of LED …

Identifying Scotomata In Hazard Identification Caused By Ignorance And Overconfidence, Allen Johanson

Masters Theses

The manufacturing and construction industries are two of the most dangerous professions, and employees are frequently exposed to hazards and hazardous conditions which can lead to serious injury or even death. An observed phenomenon, frequently called the Dunning-Kruger Effect states that unskilled people are often unaware of their shortcomings and those with the higher-level skills often underestimate their abilities. This study examines employees’ training, years of experience, and performance to gauge any correlations among these variables in the area of hazard awareness. The goal of this study is to help individuals to recognize blind spots in their knowledge to identify …

Strategies For Reducing Supplier Risk: Inputs Into The Supply Chain, Christopher A. Greene

Masters Theses

There are many aspects to consider when managing an entire supply chain from procurement to fulfillment. Complex assemblies require hundreds of components, sourced from all corners of the globe, to come together in a synchronized fashion. Given the magnitude of the supply chain, high quality standards, and significantly increased outsourcing, there is a strong need to monitor supplier risk and quickly identify and mitigate potential problems. Moreover, the continuous pressure to reduce resources and pressure to cut costs, further increases the need for the development of procedures and tools that can quickly and efficiently address these potential supply chain risks. …

Dividing And Conquering Meshes Within The Nist Fire Dynamics Simulator (Fds) On Multicore Computing Systems, Donald Charles Collins

Masters Theses

The National Institute for Standards and Technology (NIST) Fire Dynamics Simulator (FDS) provides a computational fluid dynamics model of a fire, which can be visualized by using NIST Smokeview (SMV). Users must create a configuration file (*.fds) that describes the environment and other characteristics of the fire scene so that the FDS software can produce the output file (*.smv) needed for visualization.The processing can be computationally intensive, often taking between several minutes and several hours to complete. In many cases, a user will create a file that is not optimized for a multicore computing system. By dividing meshes within the …

Modelling Supercomputer Maintenance Interrupts: Maintenance Policy Recommendations, Jagadish Cherukuri

Masters Theses

A supercomputer is a repairable system with large number of compute nodes interconnected to work in harmony to achieve superior computational performance. Reliability of such a complex system depends on an effective maintenance strategy that involves both emergency and preventive maintenance. This thesis analyzes the maintenance records of four supercomputers operational at The National Institute of Computational Science located at Oak Ridge National Laboratory. We propose to use the generalized proportional intensities model (GPIM) to model the maintenance interrupts as it can capture both the reliability parameters and maintenance parameters and allows the inclusion of both emergency and preventive maintenance. …

Requirements For A Computer Code System For The Development And Maintenance Of Target Sets, Christopher Chwasz

Masters Theses

In the field of commercial nuclear reactor security, the concept of target sets has matured since its invention in the late 1980s and early 1990s to the codification of target set regulations by the United States Nuclear Regulatory Commission in 2009 and publishing of official guidance in 2010. Target sets have evolved into a complex and useful tool to develop and test a protective strategy. By their definition, target sets are the “minimum combination of equipment or operator actions which, if all are prevented from performing their intended safety function or prevented from being accomplished, would likely result in significant …

Resilience Of Transportation Infrastructure Systems To Climatic Extreme Events, Alexandra C. Testa

Masters Theses

A topology-based approach has been used to measure the resilience of a highway network to climatic events. Civil infrastructure systems are inarguably critical to the everyday functions of society. Because such systems are regionally distributed, their components undergo a wide range of hazard intensities, often dependent on their relative locations. The ability of an infrastructure system to withstand, adapt to, and rapidly recover from extreme events is paramount to its ability to continuously serve users. The topological properties of a network can provide a good means to assess the resilience of the system which is adequate to comprehend the preparedness …

Measuring The Resilience Of Transportation Networks Subject To Seismic Risk, Mark N. Furtado

Masters Theses

Transportation networks are critical to the function of modern society but they are vulnerable to extreme events such as earthquakes. Damaged bridges can cost millions of dollars to repair and congestion and detours due to bridge closures leads to indirect costs that are even greater than the cost of repair of damaged bridges. A resilient network however should be able to limit the damage caused by earthquakes and recover in a timely fashion. Resilience of networks has been studying in length from a conceptual standpoint but as quantitative measure, the field has been lacking. This study sets forth to quantify …

A Monte Carlo Model Of Uncertainty In A Deterministic Hazardous Waste Transportation Risk Assessment, Michael A. Cowen

Masters Theses

This thesis is aimed at developing and applying advanced modeling tools in the prediction of risk to the general public from transportation of chemical waste on public highways. The modeling tools developed can then be used to compare alternative waste management scenarios. The application considered is related to the transport of hazardous waste generated by the United States Department of Energy (DOE) to current treatment, storage, and disposal facilities. DOE is currently considering four different scenarios.

The application considered can be more specifically defined as an analysis of the risk to the general public from transporting the 63 shipments of …